Universal gear coupling

ABSTRACT

A universal gear coupling including a driving and driven shaft, a housing surrounding the gears and rotatable at least with one of the shafts, a casing surrounding the housing and conduit means for circulating a lubricating fluid through the housing, the gears and the casing.

limited States Patent Monti [451 Jan. 1a, 1972 References Cited [54]UNIVERSAL GEAR COUPLING [72] Inventor:

UNITED STATES PATENTS Giancarlo Monti, Varese, Italy 1,942,101Howarth..............r......,..... 2,408,336 3,365,913 3,521,463

Shields......

[21] Appl. No.:

Primary Examiner-Kenneth W. Sprague Attorney-Kurt Kelman ForeignApplication Priority Data Dec. 24, 1968 ABSTRACT A universal gearcoupling including a driving and driven shaft, a housing surrounding thegears and rotatable at lea [52] U.S.Cl. of the shafts, a casingsurroundin [51] Int. ................Fl6d 3/18 means for circulating alubricatin 1 84/ TT, 1 4 R; the gears and the casing.

[58] Field ofSearch,............

3 Claims, 1 Drawing Figure PUMP SOURCE OF LUBRICATING FLUID HEAT EXCHWBER rmmsnmwmz PUMP HEAT SOURCE OF EXCHMGER LUBRICATING FLUID INVENTOR.cam/mm Mal/I7 BY UNIVERSAL GEAR COUPLENG The present invention relatesto a universal gear coupling, and in particular to a universal gearcoupling provided with continuous lubrication means.

Universal gear couplings with spherically shaped meshing gears are wellknown. They are commonly utilized for the continuous transmission ofhigh rotary torque from a motor shaft to a drive shaft in airplanes andsimilar high-speed vehicles. Such couplings permit the transmission ofrotary motion between misaligned or offset shafts and pennit variationin the distance between the centers of such shafts and their angulardisplacements.

Conventionally, such couplings have been grease lubricated and aircooled. The grease lubrication systems are wholly inefficient when thecoupling is operated at very high r.p.m.'s since, under centrifugalaction, the grease forms a crown within the couplings and is notuniformly distributed to the moving and meshing parts. Air-coolingsystems require the use of large heat transfer fins and other meansincluding, quite often, the use of centrifugal fans to dissipate thegenerated heat adequately.

It is an object of the present invention to provide a universal gearcoupling which is simple in construction and which is continuouslylubricated and cooled by simple and effective means.

It is another object of this invention to provide a universal gearcoupling which is lubricated and cooled by the passage of oil underpressure through the coupling, it being contemplated that the oil may berecycled and reused.

It is a specific object of the invention to provide a universal gearcoupling wherein the centrifugal forces generated by the rotation of thecouplings are utilized in the circulation of the lubricating and coolingoil.

The above objects as well as numerous advantages of the presentinvention will be seen from the following description of a now preferredembodiment thereof.

According to the present invention, a universal coupling is providedcomprising a driven shaft and a driving shaft having intermeshing gears.One of the shafts is provided with a gear housing, substantially sealedand surrounding the gears. A second housing or casing, also sealed, isformed about the first housing so that two chambers surround the gears.Lubrication fluid is fed through an inlet into the inner chamber, causedto flow about the gears, then passes to the second chamber to flow aboutthe outside of the housing, and then passes out of the casing.

in the preferred form, the lubricating fluid is oil under pressure andis fed so as to spread out and move centrifugally within inner housing.Also, the oil may be recycled and passed through a cooling system sothat cool lubricating fluid is supplied.

The following description makes reference to the accompanying drawingwhich is an axial longitudinal section of a universal coupling embodyingthe principles of the present invention.

With reference to the attached drawing it will be appreciated that thecoupling is generally symmetrical about a central longitudinal axis X.Specifically, the coupling comprises a transmission or driving shaft 1suitably connected to the output of a motor or the crankshaft of anengine, neither of which are shown. The transmission shaft 1 is providedwith a radially extending boss 1a at its inner end about the peripheryof which is formed a spherical gear 2. The gear 2 meshes with acorrespondingly formed gear ring 3 integral with the cylindrical wallportion of a substantially enclosed housing 4. The housing 4 is formedat the end of a driven shaft 5 which is supported by a suitable rollerbearing 6 secured within a stationary or fixed casing 7. The couplinghousing 4 is provided with a necked cap portion 4a which is bolted orotherwise suitably fastened thereto. The cap 40 is provided with anannular top 4b through which the shaft extends. Secured across the spacebetween the shaft 1 and the inner surface of the cover member 4a is aresilient annular packing 9 which seals the interior of the housingwhile allowing freedom of movement of the shaft.

A casing b is secured to the casing 7 so as to completely enclose thehousing and cap 4a. The top 411 of the housing cap extends through anaperture of the casing 8. The aperture is provided with a packing 10which is secured to the inner periphery of the aperture 8a but maintainsa sliding fit with the neck 4a of the housing. The sliding fit permitsfreedom of movement of the housing 4 while sealing the aperture 4aagainst leakage of fluid from within the casing. It will thus be seenthat two, substantially sealed chambers are formed about each other, onewithin the housing 4 and the other within the casing 8.

The driven shaft 5 is provided with an axial inlet channel 11 extendinginto the member 4. The channel 11 communicates with a source oflubricating fluid (preferably oil) under pressure, provided with a pumpto supply oil to the interior of the member 4 at one side of the meshinggears 2 and 3. The housing member 4 is provided with a plurality ofports 12 extend ing radially to the cylindrical wall. The ports 12 arelocated between the meshing gears 2 and 3 and the packing 9, permittingpassage of oil between the interior chamber of the housing 4 and theinterior chamber of the casing 8.

The casing 8 is itself provided with an axially extending outlet 13providing an outlet from the casing chamber. The outlet 13 is preferablyprovided with conduit means communicating with a heat exchanger or otherradiator means which will cool the oil and is provided with means forthen returning the oil to the source. Consequently, oil supplied underpressure through channel 11 will flow from the interior of the housing 4outwardly into the chamber of the casing 8 through the outlet 13 to theheat exchanger where it can be cooled and then recycled through thesource.

In operation, the coupling is rotated in conventional manner so that thedriving shaft 1 is caused to rotate the driven shaft 5. This rotationand the flexing and movement of the various parts relative to each othercreates a considerable amount of heat. Oil under pressure, preferablycooled, is fed through the channel 11 into the interior of the member 4.Upon entry into the member 4, the rotation of the parts creates acentrifugal action, forcing oil under pressure centrifugally against thecylindrical walls and through the gear teeth 2 and 3, as indicated bythe arrow A. The oil is thereafter forced through the outlets 12 intothe interior of the casing 18 where it acts to cool the exteriorsurfaces of the housing 4. From the interior of the casing 8 the oil isfed through the nipple 13 as indicated by the arrow B from where it maybe recycled or fed first into the heat exchanger and then back into thesource of pressurized oil.

It is preferred that the universal joint is initially completely filledwith lubricating oil so that, in operation, the unit may be filled withoil under pressure. Continuous flow of oil is then maintained by feedingand withdrawing uniform amounts of oil to and from the coupling. Becausethe lubricating oil may be recycled through a heat exchanger where itmay be cooled to a predetermined temperature, the coupling does notrequire any external air-cooling system and so is of simplerconstruction. Furthermore, the lubricating oil contacts all of thesurfaces of the coupling and not only those which are in direct contactwith each other. As a consequence, more effective and completelubrication and cooling is obtained.

The packings 9 and 10 assure complete sealing of the device, avoidleakage of oil under pressure, but permit universal movement of therespective parts.

While the present invention has been shown in a preferred embodiment, itis quite clear that various modifications may be made. For example, theinlet channel for the oil may be provided in the driving shaft 1 ratherthan in the driven shaft 5 and the flow of lubricating oil may bereversed so that the incoming oil enters through the nipple 13 and exitsthrough the channel 11. The form of the casing and form of the couplingmembers may otherwise be modified as is well known in this art and yetprovide for the continuous flowing of the lubricating and cooling oilthrough the coupling, as taught by the present invention. Accordingly,it is to be appreciated that the present description is by way ofillustration only and it is not to be taken as limiting of the presentinvention.

I claim:

1. in a universal gear coupling, the combination of a driving shaft anda driven shaft, a housing carried by one of said shafts and having theother shaft extending thereinto, intermeshing gears provided on saidother shaft and on the inside of said housing, flexible seal meansbetween the inside of the housing and said other shaft, the interior ofsaid housing defining a pair of internal chambers at the opposite sidesof said intermeshing gears, a stationary casing having one of saidshafts rotatably joumaled therein and surrounding said housing in spacedrelation to form an external chamber between the housing and the casing,flexible seal means provided between the casing and the housing to sealsaid external chamber, means for delivering lubricating fluid underpressure through one of said shafts into one of said pair of internalchambers, said housing being provided with fluid passages communicatingthe other of the internal chambers with said external chamber in saidcasing so that fluid delivered into said one of said internal chambersmay flow past said intermeshing gears into the other internal chamberand then through said passages into said external chamber in saidcasing, and means for discharging fluid from said external chamber.

2. The device as defined in claim 1 together with conduit means forrecycling fluid discharged from said external chamber to saidfluid-delivering means.

3. The device as defined in claim 2 together with fluid-cooling meansprovided in said conduit means.

i K i 8 i

1. In a universal gear coupling, the combination of a driving shaft anda driven shaft, a housing carried by one of said shafts and having theother shaft extending thereinto, intermeshing gears provided on saidother shaft and on the inside of said housing, flexible seal meansbetween the inside of the housing and said other shaft, the interior ofsaid housing defining a pair of internal chambers at the opposite sidesof said intermeshing gears, a stationary casing having one of saidshafts rotatably journaled therein and surrounding said housing inspaced relation to form an external chamber between the housing and thecasing, flexible seal means provided between the casing and the housingto seal said external chamber, means for delivering lubricating fluidunder pressure through one of said shafts into one of said pair ofinternal chambers, said housing being provided with fluid passagescommunicating the other of the internal chambers with said externalchamber in said casing so that fluid delivered into said one of saidinternal chambers may flow past said intermeshing gears into the otherinternal chamber and then through said passages into said externalchamber in said casing, and means for discharging fluid from saidexternal chamber.
 2. The device as defined in claim 1 together withconduit means for recycling fluid discharged from said external chamberto said fluid-delivering means.
 3. The device as defined in claim 2together with fluid-cooling means provided in said conduit means.